This proposal is for matching funds to purchase a new cyclotron to replace our existing 21 year old biomedical cyclotron that is failing due to its advanced age and obsolete technology. The cyclotron provides all the necessary positron labeled compounds for our funded research studies of the biochemical and biological mechanisms of normal human brain development and neuronal plasticity, including the compensatory reorganization of the brain following injury, disease or surgery. It is critical to our studies of developmental disorders, pediatric. and adult epilepsy, Alzheimer's, Parkinson's, Huntington's, depression/mania, drug abuse, coronary artery disease, cardiomyopathies and cancer of the breast, lung, bone, brain, liver and lymphic system. Without the cyclotron, it would be impossible for us to continue any of these funded research projects. These projects involve approximately $3.2 million per year of NIH and $3.4 Million of DoE funded research all of which are completely dependent upon the cyclotron facility. We have raised 88.6 % of the required funding by obtaining a significant discount on the equipment from the vendor, obtaining a supplementary grant from DoE and soliciting private donations. Since DoE funds a significant fraction of the research projects with the cyclotron, we requested and received a $908,000. In addition, we also obtained $455,000 from the Ahmanson Foundation to apply to this purchase. The existing research grants will provide the necessary maintenance and operating support for the cyclotron. The administration of the cyclotron is carried out by a Resource Allocation Committee (RAC) that consists of the PIs of the major grants and representatives of the technology components (i.e., cyclotron chemistry, PET scanners and animal laboratories). This administrative configuration has been in effect for 15 years and has efficiently allocated the resources of the cyclotron and other major instruments.